If your fast and are really regretting it, you might be able to call and get your order changed. I've found most shops don't ship for a couple of days. Still, the 24" version is scarcer than the 16.5", if you hate it, it likely won't be hard to sell off the barrel and replace it with a factory takeoff ( or custom) in a shorter length. . That said, I always found it odd that this model isn't offered in the 20" barrel length as well . Seems like that's the happy place for allot of .22 rifle buyers. FWIW, I have two CZ 457's. One custom build (22") and a Royal (20"). I wouldn't sell either for more than I paid for them. In fact, I'm considering a third.
In any case, keep us posted on how you like it!